1. Field of the Invention
This invention relates to the development and management of transactions on the Internet.
2. Background
The Internet is a worldwide matrix of interconnected computers. An Internet client accesses a computer on the network via an Internet provider. An Internet provider is an organization that provides a client (e.g., an individual or other organization) with access to the Internet (via analog telephone line or Integrated Services Digital Network line, for example). A client can, for example, download a file from or send an electronic mail message to another computer/client using the Internet.
To retrieve a file on the Internet, a client must search for the file, make a connection to the computer on which the file is stored, and download the file. Each of these steps may involve a separate application and access to multiple, dissimilar computer systems. The World Wide Web (WWW) was developed to provide a simpler, more uniform means for accessing information on the Internet.
The components of the WWW include browser software, network links, and servers. The browser software, or browser, is a graphical interface (i.e., front-end) that simplifies access to the Internet. A browser allows a client to communicate a request without having to learn a complicated command syntax. A browser typically provides a graphical user interface (GUI) for displaying information and receiving input. Examples of browsers currently available include Mosaic, Netscape, and Cello.
Information servers maintain the information on the WWW and are capable of processing a client request. Hypertext Transport Protocol (HTTP) is the standard protocol for communication with an information server on the WWW. HTTP has communication methods that allow clients to request data from a server and send information to the server.
To submit a request, the client contacts the HTTP server and transmits the request to the HTTP server. The request contains the communication method requested (e.g., GET an object from the server or POST data to an object on the server). The HTTP server responds to the client by sending a status of the request and the requested information. The connection is then terminated between the client and the HTTP server. A connection between a client and an HTTP server therefore has four stages: 1) initiation, 2) request transmittal, 3) response transmittal, and 4) termination. A connection can only process a single transaction or interaction between the client and the HTTP server.
The HTTP server does not retain any information about the request after the connection has been terminated. HTTP is, therefore, a stateless protocol. That is, a client can make several requests of an HTTP server, but each individual request is treated independent of any other request. The server has no recollection of any previous request.
An addressing scheme is employed to identify Internet resources (e.g., HTTP server, file or program). This addressing scheme is called Uniform Resource Locator (URL). A URL contains the protocol to use when accessing the server (e.g., HTTP), the Internet domain name of the site on which the server is running, the port number of the server, and the location of the resource in the file structure of the server.
The WWW uses a concept known as hypertext. Hypertext provides the ability to create links within a document to move directly to other information. To activate the link, it is only necessary to click on the hypertext link (e.g., a word or phrase). The hypertext link can be to information stored on a different site than the one that supplied the current information. A URL is associated with the link to identify the location of the additional information. When the link is activated, the client's browser uses the link to access the data at the site specified in the URL.
If the client request is for a file, the HTTP server locates the file and sends it to the client. An HTTP server also has the ability to delegate work to gateway programs. The Common Gateway Interface (CGI) specification defines the mechanisms by which HTTP servers communicate with gateway programs. A gateway program is referenced using a URL. The HTTP server activates the program specified in the URL and uses CGI mechanisms to pass program data sent by the client to the gateway program. Data is passed from the server to the gateway program via command-line arguments, standard input, or environment variables. The gateway program processes the data and returns its response to the server using CGI (via standard input, for example). The server forwards the data to the client using the HTTP.
A browser displays information to a client/user as pages or documents. A language is used to define the format for a page to be displayed in the WWW. The language is called Hypertext Markup Language (HTML). A WWW page is transmitted to a client as an HTML document. The browser executing at the client parses the document and produces a displays a page based on the information in the HTML document.
HTML is a structural language that is comprised of HTML elements that are nested within each other. An HTML document is a text file in which certain strings of characters, called tags, mark regions of the document and assign special meaning to them. These regions are called HTML elements. Each element has a name, or tag. An element can have attributes that specify properties of the element. Blocks or components include unordered list, text boxes, check boxes, radio buttons, for example. Each block has properties such as name, type, and value. The following provides an example of the structure of an HTML document:
&lt;HTML&gt; PA1 &lt;/HTML&gt;
&lt;HEAD&gt; PA2 . . . element(s) valid in the document head PA2 &lt;/HEAD&gt; PA2 &lt;BODY&gt; PA2 . . . element(s) valid in the document body PA2 &lt;/BODY&gt;
Each HTML element is delimited by the pair of characters "&lt;" and "&gt;". The name of the HTML element is contained within the delimiting characters. The combination of the name and delimiting characters is referred to as a tag. Each element is identified by its tag. In most cases, each element has a start and ending tag. The ending tag is identified by the inclusion of an another character, "/" that follows the first delimiting character ("&lt;").
HTML is a hierarchical language. With the exception of the HTML element, all other elements are contained within another element. The HTML element encompasses the entire document. It identifies the enclosed text as an HTML document. The HEAD element is contained within the HTML element and includes information about the HTML document. The BODY element is contained within the HTML. The BODY element contains all of the text and other information to be displayed. Other elements are described by any HTML reference manual.
Web-based access has been used for simple information publishing that consisted of static data and no logic. For example, a client request might request another page. The HTTP server fetches a pre-defined Web page using the URL contained in the request. The Web page is returned to the client. Web-based access has progressed to dynamic information publishing that allows some simple queries and some limited logic to access a database and display database information. Web applications have been used in commerce to order articles of manufacture via the Web (e.g., a personal stereo cassette deck). Commerce applications provide some limited logic and allow a Web page to change based on the client input.
Web-based applications are developed independent of other Web-based applications. That is, constructs used to implement one Web-based application remain local to the application. They are not shared.
Currently, a common gateway interface program is written to process a single transaction. Minimal state information is retained within the HTML document. It would be beneficial to use object-oriented HTML elements to manage a series of Internet transactions and to maintain state information across Internet transactions. It would be beneficial to be able to generate HTML documents dynamically using information from a previous transaction, corporate data, and data retained in HTML element objects. It would be beneficial to be able to share application development across applications.